Hmm, there is an annoyance. } is specified in terms of {, and:
$(1 0;0 1){i.2 2
2
$(,<1 0){i.2 2
1
$''{i.2 2
0 2
On the other hand, it's _really_ annoying that the original code doesn't work.
Thoughts--would it be permissible for } to be more relaxed here? It is
difficult because implementation cannot know what sort of empty list was
intended; being lax may also hide bugs. I am not sure if that is likely to
come up, though. Passing an empty list to { or } is a degenerate case, since
it does not perform useful work or produce useful results. Therefore, any
context in which '' is passed to { or } is one in which a nonempty list will
also be passed at some point, and if the latter is malformed, the problem will
be diagnosed and the error signalled then.
On Sun, 19 Jun 2022, Elijah Stone wrote:
'' ''} i.2 2
|length error
| '' ''}i.2 2
Should it be an error? I would expect it not to be, because:
(,27) (,<1 0)} i.2 2
0 1
27 3
(27 28) (1 0;0 1)} i.2 2
0 28
27 3
So the original snippet is just the degenerate case where no indices are
supplied. But I want to ensure I am not missing anything obvious.
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
